Fibrous material with high functional particle load

ABSTRACT

This invention relates to fibrous absorbent articles containing particles useful in the manufacture of disposable diapers, adult incontinence pads, sanitary napkins and the like. More particularly, the invention is directed to a multistrata fibrous web including a plurality of first strata including matrix fibers and thermoplastic fibers and a plurality of second strata including functional particles arranged in separated lanes. The first and second strata alternate through the web and the lanes of the second strata are arranged such that such that the lanes of adjacent second strata do not superimpose.

FIELD OF THE INVENTION

This invention relates to fibrous material, including fibrous structurescontaining particle, which are useful in the manufacture of disposablediapers, adult incontinence pads, sanitary napkins and the like. Moreparticularly, the invention is directed to fibrous articles having veryhigh loads of particles, particularly particles of superabsorbentpolymer.

BACKGROUND OF THE INVENTION

Absorbent articles such as disposable diapers, adult incontinence pads,sanitary napkins, panty liners and the like, are generally provided withan absorbent core to receive and retain body liquids. The absorbent coreis usually sandwiched between a liquid pervious top sheet, whosefunction is to allow the passage of fluid to the core, and a liquidimpervious backsheet, whose function is to contain the fluid and toprevent it from passing through the absorbent article to the garment ofthe wearer of the absorbent article.

An absorbent core for diapers and adult incontinence pads frequentlyincludes fibrous batts or webs constructed of defiberized, loose,fluffed, hydrophilic, cellulosic fibers. The core may also include alayer or stratum containing superabsorbent polymer (SAP) particles,granules, flakes or fibers, often referred to as the storage layer orstratum.

In recent years, market demand for an increasingly thinner and morecomfortable absorbent article has increased. Such an article may beobtained by decreasing the thickness of the diaper core, by reducing theamount of fibrous material used in the core while increasing the amountof SAP particles, and by calendering or pressing the core to reducecaliper and hence, increase density.

Such higher density cores do not absorb liquid as rapidly as lowerdensity cores because the compacting of the core (densification) resultsin smaller effective pore size. Accordingly, to maintain suitable liquidabsorption, it is necessary to provide a lower density layer having alarger pore size above the high-density absorbent core to increase therate of uptake of liquid discharged onto the absorbent article. Thelow-density layer is typically referred to as an acquisition layer.Multiple layer absorbent core designs involve a more complicatedmanufacturing process.

The storage layer portion of a disposable diaper for example, isgenerally formed in place, during the converting process, from loose,fluffed cellulose. Such cellulose material is generally not available inpreformed roll form because it exhibits insufficient web strength, owingto its lack of interfiber bonding or entanglement, to be unwounddirectly onto and handled in absorbent pad-making equipment.

Ultra-thin feminine napkins are generally produced from roll-goods basednonwoven material. Such a roll of preformed absorbent core material isunwound directly onto the absorbent article converting equipment withoutthe defiberization step required for fluff-based products, such asdiapers and incontinence pads. The nonwoven web is typically bonded orconsolidated in a fashion that gives it sufficient strength to behandled in the converting process. These webs may also contain SAPparticles.

The web consolidation mechanisms used in the roll-goods approach tomaking preformed cores provide strength and dimensional stability to theweb. Such mechanisms include latex bonding, bonding with thermoplasticor bicomponent fibers or thermoplastic powders, hydroentanglement,needle punching, carding or the like. At high particle loading, however,the core structures exhibit poor particle containment. In other words,some of the particles tend to escape from the structure duringmanufacture, handling, shipping and converting and in use. This canresult in the fouling of manufacturing and converting equipment as wellas negative consumer perception of the product.

There is a need for an absorbent core material which facilitates fluidtransport from an acquisition zone to a storage zone, exhibits goodparticle containment at high particle loading, provides high pliabilityeven at high particle loading, is thin but has a high absorbent capacityin use, and can be delivered in roll-goods form to simplify themanufacturing and converting processes.

Published PCT application WO 00/71790 discloses an absorbent articleincluding a layer of functional particles, optionally provided in lanes,wherein the lateral edges of the article are free of functionalparticles and may be sealed to contain loose particles within thestructure.

It is an object of the invention to provide a fibrous web comprisingfunctional particles present at high loading, which can be formed intoabsorbent articles.

It is another object of the invention to provide a method of making afibrous web including functional particles present at high loading,which can be formed into absorbent articles.

It is another object of the invention to provide an improved fibrousmaterial including a high load of functional particles and exhibits highpliability.

SUMMARY OF THE INVENTION

In one embodiment this invention is a material including

-   -   (A) from about 60 weight percent to about 95 weight percent SAP,    -   (B) from about 5 weight percent to about 40 weight percent        fibers,    -   (C) from about 0.1 weight percent to about 30 weight percent        total binder, and having    -   (D) a basis weight of from about 100 to about 1000 gsm.    -   (E) a density of from about 0.15 g/cc to about 3 g/cc, the        material having    -   (F) a thickness Z dimension of from about 0.3 mm to about 3 mm,        and    -   (G) a pliability of about 400 I/N or greater.

In one embodiment the material comprises from about 0.1 weight percentto about 10 weight percent total binder which comprises a first binder,a second binder, and, optionally, a third binder, where each binder canbe the same as or different from any other binder. The material mayfurther comprise (H) a carrier, which may be a cellulosic tissue carrieror a synthetic material. The material may further comprise

-   -   (I) a layer consisting essentially of        -   (a) synthetic fibers, and        -   (b) a third binder.

In one embodiment the material has

-   -   (J) a machine direction X dimension of from about 1 cm to about        1000 m,    -   (K) a cross machine direction Y dimension of from about 2 cm to        about 5 m, and the material is in a substantially rectangular        format and from about 90 weight percent to about 100 weight        percent of the SAP in the material is located in SAP domains        with a longest dimension aligned substantially in the machine        direction X of the material.

In another embodiment this invention is a nonwoven material with apliability of about 400 1/N or greater comprising from about 75 to about95 weight percent SAP.

In another embodiment this invention is a process for the production ofa material comprising depositing on a removable support, a carrier or ona carrier on a support a mixture of SAP, fibers and binder, where thematerial comprises from about 60 weight percent to about 95 weightpercent SAP and has a pliability of about 400 I/N or greater.

Preferred aspects are those wherein:

-   -   (a) a layer of fibers and binder is deposited on a moving        removable support, a carrier or on a carrier on a support to        form a web, the movement being in a machine direction X,    -   (b) SAP is deposited in discreet lanes on the web of (a) in the        machine direction, the lanes being spaced apart in the cross        machine direction Y at a right angle to the machine direction,    -   (c) a second layer of fibers and binder is deposited on the        moving web,    -   (d) a second layer of SAP is deposited in discrete lanes on the        web of (c) in the machine direction, the lanes being spaced        apart in the cross machine direction, where the SAP lanes of the        second layer are not superimposed on the SAP lanes of the first        layer when viewed from a thickness direction Z at right angles        to the X and Y directions,    -   (e) optionally repeating steps (c) and (d) one or more times,    -   (f) heating the web one or more times to activate the binder,        and    -   (g) optionally densifying the web.

In another embodiment this invention includes an absorbent core having:

-   -   (1) a material of one referred to above in combination with    -   (2) a second material,        where the second material is a second layer of the material of        (1), a material referred to above which is not the material of        (1), or a second material which is not a material referred to        above. The absorbent core may two of the materials of the        invention or one or more of the materials of the invention in        combination with a conventional unitary core, an acquisition        distribution structure or some other structure. Structures of        this type may be referred to as DUOCORE structures, the        conventional aspects of which are generally described in WO        00/41882, which is hereby incorporated by reference in its        entirety.

The material of the invention as well as a core of this type can beproduced in a continuous process which is a series of unit operations,preferably including unit operations involving airlaying of fibrousmixtures through individual airlaying heads. The absorbent core may alsobe produced with adhesives in a conventional converting operation.

The materials of this invention and cores containing them are useful invarious fields including us in absorbent products in the form of adiaper, training pant, incontinent device, feminine hygiene device,surgical drape, wound dressing, or cable wrap.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a functional particle stratum made according tothe present invention, showing multiple lanes of particle material,forming particle-free zones or spaces.

FIG. 2 is a top view of a functional particle stratum made according tothe present invention, showing multiple lanes of particle material,forming particle-free zones or spaces.

Here the lanes are offset from the lanes of the stratum of FIG. 1.

FIG. 3 is a cross-sectional view of a fibrous web or article madeaccording to the present invention showing alternating matrix fiberstrata and functional particle strata.

FIG. 4 is a top view of a functional particle stratum made according tothe present invention, showing multiple lanes of particle material,wherein the lanes are S-shaped.

FIG. 5 is a top view of a functional particle stratum made according tothe present invention, showing multiple lanes of particle material,wherein the lanes are hourglass-shaped.

FIG. 6 is a top view of a functional particle stratum made according tothe present invention, showing multiple lanes of particle material,wherein the lanes are circle-shaped.

FIG. 7 is a top view of a functional particle stratum made according tothe present invention, showing multiple lanes of particle material,wherein the lanes are intermittent.

FIG. 8 schematically shows a production line for a method of formingabsorbent articles comprising an absorbent core according to the presentinvention. FIG. 8 a is a cross-sectional view of the production line ofFIG. 8.

FIG. 9 is a schematic view of a lane divider.

FIG. 10 is a schematic view of a test apparatus foracquisition/rewet/wicking distance test.

FIG. 11 is a schematic view of the folding of an absorbent core of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

All patent and patent applications cited in this specification arehereby incorporated by reference into this specification. In case ofconflict in terminology, the present disclosure controls.

The present invention is directed to a stratified fibrous web whichcomprises a plurality of functional particle strata. Each functionalparticle stratum includes lanes or zones of functional particles, andeach lane or zone is separated from an adjacent lane or zone.

Adjacent functional particle strata are oriented such that when viewingthe web in the Z-direction, the functional particle lane or zone of onefunctional particle stratum does not directly overlay, or superimpose, afunctional particle lane or zone from the next adjacent functionalparticle stratum. In other words, the lanes or zones for a firstfunctional particle strata are offset from the lanes or zones of thenext adjacent functional particle strata.

With reference to FIG. 1, there is shown a top view of a functionalparticle stratum. In a preferred embodiment, the structures of thepresent invention are prepared using airlaid technology. For purposes ofreference, the Figures show the structures of the present invention aselongated in the MD or machine direction, also referred to as theY-direction. The CD or cross-direction is perpendicular to the MD.Finally, the Z-direction refers to the thickness of the structure and isorthogonal to the X-Y plane.

Stratum 2 of FIG. 1 includes a plurality of lanes 6 and 8 extendinglongitudinally in the Y-direction. Each lane includes functionalparticles. The edges 10 of stratum 2 are free of functional particles.Between each lane are spaces 14, also free of functional particles.Stratum 2 may be applied over another functional particle stratum orover another stratum not containing functional particles. Referring toFIG. 2, a second functional particle stratum 4 is shown. This stratumalso includes longitudinally extending lanes of functional particles.However, the lanes are positioned such that when stratum 2 is appliedover stratum 4 the lanes will not superimpose, when viewed in theZ-direction. Similarly, the lanes of stratum 2 will not superimpose overthe lanes of stratum 4, even when an intervening stratum not containingfunctional particles is placed between strata 2 and 4.

The spaces 14 between lanes in strata 2 and 4, preferably aresubstantially free of functional particles, fibers or any othermaterial. Optionally, non-functional material such as fibers may beprovided between the lanes. During the manufacturing process, some minorportion of the particles may migrate from the lanes to the spaces beforethe fibers are fixed in place by curing of fibers, without adverseeffect.

With reference to FIG. 3, there is shown a cross-section (taken in theX-direction) of a multistrata structure according to the presentinvention including a plurality of functional particle strata. A firststratum 16 not containing functional particles, and preferablycontaining matrix fibers and a binder is provided. Over stratum 16 isprovided stratum 4, including lanes 12 of functional particles withspaces 14 between the lanes free of particles or fibers. Stratum 18 isprovided over stratum 4. Stratum 2 is then positioned over stratum 18such that lanes 6 and 8 of the stratum do not superimpose on the lanesof stratum 4. Again, it is preferred that spaces 14 of stratum 2 arefree of particles or fibers. Stratum 20 is provided over stratum 2.Another stratum 4 is positioned over stratum 20 such that lanes 12 donot superimpose on lanes 6 or 8 of stratum 2. Finally, stratum 22 isprovided over stratum 4. Each of strata 18, 20 and 22 contains nofunctional particles and contains the same or different types and amountof fibers as either strata or each other.

The resultant multistrata structure includes alternating strata offibers and functional particles, such that the lanes of functionalparticles are substantially surrounded by fibers.

The lateral edges of the multistrata structure of FIG. 3 are optionallyprovided with an edge seal as described in PCT application WO 00/71790the disclosure of which is hereby incorporated by reference.

The multistrata structure of FIG. 3 is depicted for illustrativepurposes as having three functional particle strata. However, thestructure may contain as few as two such strata or as many as issuitable for a particular application. In a preferred embodiment, sixsuch strata are provided.

The multistrata structure of FIG. 3 may itself be included with otherstrata in a unitary multilayer structure, to provide for example, astructure having specified fluid acquisition, distribution and storagecapabilities.

Lanes

The lanes of the functional particle strata are shown in FIGS. 1-3 asbeing parallel and extending continuously in the MD or Y-direction ofthe strata. However, lanes or zones (hereinafter collectively referredto as “lanes”) may be arranged in other ways suitable to the presentinvention. For example, the lanes can remain as parallel but theparticles may be provided intermittently to provide lane segments withgaps between the segments, as shown in FIG. 7. Alternatively, the lanescan be applied in a S-shape in the longitudinal direction with S-shapedspaces between the lanes, as shown in FIG. 4. Alternatively, the lanesmay be hour-glass shaped, as shown in FIG. 5. Other patterns may be usedas well, such as circle-shaped (FIG. 6). However, it is important thateach functional particle stratum contain both lanes containingfunctional particles and spaces not containing functional particles, andthe pattern must be arranged such that lanes or zones of a firstfunctional particle stratum will not superimpose over the lanes or zonesof a second next adjacent functional particle stratum. Notwithstandingthe foregoing, superimposition of a small percentage (less than 15%) ofthe area of lanes or zones, is considered to meet this definition.

The preferred amount of coverage of a given functional particle stratumby the functional particles depends upon the application and thethickness, density and other parameters of the particles. Generally, itis preferred that the lanes of the stratum cover at least 30% andpreferably 40% and most preferably 50% of the X-Y area of the stratum.

Functional Particles

The functional particle lane is intended to receive particles, flakes,powder, granules, or the like.

The particles may include any functional powder or other particleshaving a particle diameter of up to 3,000 microns (μ). The particle areamay include a particle loading of from 2 to 2,000 gsm (grams per squaremeter), more preferably from 2 to 1,000 gsm, even more preferably from10 to 600 gsm, and most preferably from 100 to 250 gsm.

The particles may be superabsorbent polymers (“SAP”) or other functionalmaterial. Other suitable particles include odor control agents, e.g.,zeolites or calcium carbonate, fragrances, detergents and the like.

A superabsorbent polymer is a water soluble compound that has beencross-linked to render it water insoluble but still swellable to atleast about 15 times its own weight in physiological saline solution.These superabsorbent materials generally fall into three classes, namelystarch graft copolymers, cross-linked carboxymethylcellulosederivatives, and modified hydrophilic polyacrylates. Examples ofabsorbent polymers include hydrolyzed starch-acrylontrile graftco-polymer, saponified acrylic acid ester-vinyl co-polymer, modifiedcross-linked polyvinyl alcohol, neutralized cross-linked polyacrylicacid, cross-linked polyacrylate salt, and carboxylated cellulose. Thepreferred superabsorbent materials, upon absorbing fluids, formhydrogels.

The superabsorbent polymer materials have relatively high gel volume andrelatively high gel strength as measured by the shear modulus of thehydrogel. Such preferred materials also contain relatively low levels ofpolymeric materials which can be extracted by contact with syntheticurine. Superabsorbent polymers are well-known and are commerciallyavailable. One example is a starch graft polyacrylate hydrogel marketedunder the name IM 1000 (Hoechst-Celanese, Portsmouth, Va.). Othercommercially available superabsorbent polymers are marketed under thetrademark Sanwet (Sanyo Kasei Kogyo Kabushiki, Japan), Sumika Gel andSA60S (Sumitomo Kagaku Kabushiki Haishi, Japan), Favor (Stockhausen,Garyville, La.), Kolon GS3500 superabsorbent polymer granules, Kolon,Korea; and the ASAP series (Chemdal, Aberdeen, Miss.). Superabsorbentparticulate polymers are also described in detail in U.S. Pat. Nos.4,102,340 and Re. 32, 649. An example of a suitable SAP is surfacecross-linked acrylic acid based powder such as Stockhausen 9350 or SXFAM 70 (Greensboro, N.C.).

Fibers

The fibers suitable for use in the structures of the present inventionmay include cellulosic or synthetic fibers or blends thereof. Mostpreferred is wood cellulose. Also preferred is cotton linter pulp,chemically modified cellulose such as crosslinked cellulose fibers andhighly purified cellulose fibers, such as Buckeye HPF (each availablefrom Buckeye Technologies Inc., Memphis, Tenn.). The fluff fibers may beblended with synthetic fibers, for example polyester such as PET, nylon,polyethylene or polypropylene.

The fiber-containing strata may also include thermoplastic bindingmaterial, which may be blended with the cellulosic or synthetic fibers.Suitable thermoplastic binding material includes thermoplastic fibers,such as bicomponent thermoplastic fibers (“bico”). Preferredthermoplastic binding fibers provide enhanced adhesion for a wide rangeof materials, including synthetic and natural fibers, particles, andsynthetic and natural carrier sheets. An exemplary thermoplastic bicofiber is Celbond Type 255 Bico fiber from Hoechst Celanese.

Other suitable thermoplastic fibers include polypropylenes, polyesters,nylons and other olefins, or modifications thereof. A preferredthermoplastic fiber is FiberVisions type AL-Adhesion-C BicomponentFiber, which contains a polypropylene core and an activated copolyolefinsheath.

When the matrix fibers are cellulosic or synthetic fibers (or blendsthereof), each stratum positioned between the functional particle stratamay preferably contain from about 1 to 20 gsm of cellulosic of syntheticfibers. A thermoplastic bonding material may be present in the stratumin the amount of 2 to 50% by weight, more preferably 3 to 20%, mostpreferably about 10% of the total weight of the stratum. Mostpreferably, the stratum between the functional particle strata includes3.0 gsm fluff pulp and 1.0 gsm of bico.

Binders

Aside from the thermoplastic fibers discussed above, other suitablebinders for use in the structures of the invention include binders inliquid form or having a liquid carrier, including latex binders. Usefullatex binders include vinyl acetate and acrylic ester copolymers,ethylene vinyl acetate copolymers, styrene butadiene carboxylatecopolymers, and polyacrylonitriles, and sold, for example, under thetrade names of Airbond, Airflex and Vinac of Air Products, Inc., Hycarand Geon of Goodrich Chemical Co., and Fulatex of H. B. Fuller Company.Alternatively, the binder may be a non-latex binder, such asepichlorohydrin and the like.

The invention contemplates two separate binder applications. In thefirst application, the binder is applied to the structure so as tocontact only the particle free area or lane, which is adjacent the areasor lanes containing the particles disposed between the first and secondlayers. The binder may be applied in the form of a spray, foam, or mist.In preferred embodiments, the binders are diluted to contain 3 to 25%solids, more preferably 6 to 12% solids, most preferably 10%.

A binder which is diluted to have a relatively high solids content (suchas 10%) is ideal for acting in the highly compacted, small poreenvironment of the particle free area, wherein the seals are formed. Theenvironment results in fast wicking, and the high solids content reducesmigration of the binder to the other areas of the web.

The second binder application involves application of a binder, in theform of a foam, spray or mist, to substantially the entire surface ofthe structure (as an “overall binder”), in order to reduce dust-off onthe exterior and interior of the structure. In preferred embodiments,the overall binders are diluted to contain 1 to 20% solids, morepreferably 2 to 10% solids, even more preferably 2 to 4% solids, andmost preferably about 3.5% solids. While the binder will penetrate toreduce dust-off and to immobilize the functional particles, it will notprovide a significant contribution to the structural integrity of theweb.

The use of two binder applications allows independent control of theseal area stiffness and the non-seal area stiffness. The stiffness ofeither region can be controlled by the selection of binder type, solidscontent and amount of binder applied to the respective regions. Thisaddresses the need to deliver requisite seal strength and maintainsufficient flexibility for the comfort of the user.

Seals

The fibers of the structures of the present invention may be fixed inplace to provide integrity to the structure using heat-activated fibersor other binding agents. In certain embodiments a thermoplastic bindingmaterial is used and seals are formed when the structure is compacted ordensified by pressure or pressure and heat. The seals may be furtherstrengthened by subsequent curing in a curing oven. It is preferred touse thermoplastic fibers as the binder fiber, and heat as the curingagent. Heat can be applied to cure the fibers at the end of theairlaying process, or alternatively, periodically at various stages ofthe process.

In an alternative embodiment, the sealing may be provided by theapplication of a liquid binder (or binder in a liquid carrier), aftercompacting or densification of the web. In such embodiments, the binderis targeted to contact the particle-free areas, and to avoid theparticle areas. The binder wicks into the densified region, and formsseals upon drying and curing. Further, in these embodiments, the upperand lower strata optionally contain a thermoplastic binding material.

In another embodiment, seals are formed by application of a liquidbinder (or a binder in a liquid carrier) in the particle free zone only,wherein the binder wicks into the densified region and forms strongseals upon drying and curing, without densification of the particle freezone.

In preferred embodiments, seals are formed by compacting ordensification of the particle-free areas, followed by application of abinder which is targeted to contact the particle-free areas, and toavoid the particle areas. The binder wicks into the densified region,and forms seals upon drying and curing. In these preferred embodiments,the upper and lower strata each contain a thermoplastic bindingmaterial, which strengthens the seals upon densification and curing.

The heat seals are substantially free of functional particles, and theresultant seal is stronger than a seal having particles at the sealinterface. When the structure of the invention is subjected to a liquidinsult, there are substantially no particles (such as SAP particles)within the sealed area which can swell and disrupt the integrity of theseal.

In certain embodiments of the invention, the article is an absorbentarticle.

The fibrous structure having improved particle containment may bedelivered in roll-goods form, or in other packaging formats such asfestooning, and is particularly useful as an absorbent core fordisposable absorbent articles such as diapers, adult incontinence padsand briefs, and feminine sanitary napkins.

Airlaid Manufacture of a Structure of the Invention

Preferably, the structure of the present invention is prepared as anairlaid web. The airlaid web is typically prepared by disintegrating ordefiberizing a cellulose pulp sheet or sheets, typically by hammermill,to provide individualized fibers. The individualized fibers are then airconveyed to forming heads on the airlaid web forming machine. Severalmanufacturers make airlaid web forming machines, including M&J Fibretechof Denmark and Dan-Web, also of Denmark. The forming heads includerotating or agitated drums, generally in a race track configuration,which serves to maintain fiber separation until the fibers are pulled byvacuum onto a foraminous condensing drum or foraminous forming conveyor(or forming wire). Other fibers, such as a synthetic thermoplasticfiber, may also be introduced to the forming head through a fiber dosingsystem which includes a fiber opener, a dosing unit and an air conveyor.Where multiple layers are desired, such as a distribution layer and anacquisition layer, separate forming heads may be provided for each typeof layer.

In preferred embodiments, the material and structures of the inventioncontain a carrier tissue. Optionally the use of a compaction roll priorto the introduction of the particle areas can be used to eliminate theneed for the tissue.

As contemplated by the present invention, one or more forming heads ofthe airlaid web forming machine distributes the desired fiber for thelower layer of the absorbent structure.

SAP granules or other particles are then applied to the upper surface ofthis web. The particles are applied in lanes in the machine directionwith particle-free zones or lanes therebetween. Other particles includeodor control agents, e.g., zeolites or calcium carbonate, fragrances,detergents and the like.

A second layer is then formed over the top of the lower layer having theparticles applied thereto. Another stratum of SAP granules or otherparticles are then applied to the upper surface in lanes. The lanes areapplied such that the granules do not superimpose over the granules inthe particle-containing stratum below. Subsequent alternating layers offibers and granules may be added as desired.

FIG. 6 depicts a process of making a fibrous web according to thepresent invention.

Optionally, a carrier tissue 20 a may be unwound from the supply roll21. The tissue 20 a is rolled on to screen 18. The tissue mayalternatively be used as a carrier or as the lower stratum 16 of theabsorbent article. As contemplated for the present invention, a forminghead 24 of the airlaid web-forming machine distributes the desired fiberto form the lower stratum 16 of the absorbent structure. Cellulosicfibers may be obtained by disintegrating or defiberizing a cellulosepulp sheet or sheets, typically by hammermill, to provide individualizedfibers. The individualized fibers are then air conveyed to forming headson the airlaid web-forming machine. Cellulosic fiber and optionallythermoplastic fibers are added to the cellulose tissue 20 a by forminghead 24.

Several manufacturers make airlaid web forming machines, including M&JFibretech of Denmark and Dan-Web, also of Denmark. The forming headsinclude rotating drums, or agitators generally in a racetrackconfiguration, which serve to maintain fiber separation until the fibersare pulled by vacuum onto a foraminous condensing drum or foraminousforming conveyor (or forming wire). For example, in machinesmanufactured by M&J Fibretech, the forming head includes a rotaryagitator above a screen. Other fibers, such as a synthetic thermoplasticfiber, may also be introduced to the forming head through a fiber dosingsystem, which includes a fiber opener, a dosing unit and an airconveyor. Where multiple strata are desired, such as a fluff pulpdistribution stratum and a synthetic fiber acquisition stratum, multipleforming heads are provided, one for each type of stratum.

In a nip formed by a pair of calender rolls 26, the fibers areoptionally compressed to the desired thickness and density. The lowerstratum 16 may be compacted at this point in the manufacturing processto close the pores of the web if the particles are fine and to preventspillage on to the forming wire.

Particles are applied to the lower stratum 16 by particle applicator 28.SAP granules or other particles are thus applied to the upper surface ofthe lower stratum 16. Referring now to FIG. 7, the particles are appliedin a plurality of lanes 6 in the machine direction with particle-freezones or lanes 8 located between the particle lanes. Lanes are areas inwhich particles are specifically delivered. Other suitable particlesinclude odor control agents, e.g., zeolites or calcium carbonate,fragrances, detergents and the like.

A second strata of fibers 18 is applied by forming head 34, whichapplies cellulosic fibers, and optionally can also apply a thermoplasticfiber such as a bicomponent fiber. Subsequent layers can be added on topof the second layer.

After the second stratum is applied the web may pass under anotherparticle applicator 28 (not shown) to apply another stratum ofparticles, followed by another stratum of fibers applied by anotherforming head 34 (not shown). In this way, the web may be built up by adesired number of alternating strata of fibers and particles.

A series of ovens is used in processes of the invention, for drying,curing or thermal bonding.

The airlaid web 23 is heated to a temperature in the range of from 125to 180° C. at oven 50. When thermoplastic fibers are used, includingpreferably bico fibers, the curing temperature and dwell time must besufficient to melt the fibers and cause binding. An overall binder isapplied to the airlaid web 23 at 52. This binder can be applied byspray, foam or mist, and is applied to reduce dust-off on the surface ofthe structure.

The air laid web 23 is heated in a second oven 54 at a temperature inthe range of from 125 to 180° C. The airlaid web 23 can be treated atpressure in the range of from 0.1 to 10 psi, preferably 1.5 psi. As aresult of this process, heat seals between the thermoplastic materialand the fibers of the upper and lower layers are formed. The heat sealsare substantially free of particles (especially SAPs), which coulddisrupt the heat seal upon exposure to moisture. The finished web isthen rolled for future use. This continuous band of fibrous web can beslit or cut to form individual absorbent articles in a cutting unit,which has not been depicted in this figure.

Optionally, the finished web may be slit or perforated at the heat sealto yield narrow slit core material having a heat seal along both edges.The heat seals to be slit must be of sufficient width to provide twoeffective seals after slitting.

In other embodiments, various other layers containing other types andamounts of fibers may be applied above or below the upper and lowerlayers of the structure of the present invention. For example, theabsorbent article may also contain a fluid previous top sheet and afluid impervious backsheet. Exemplary absorbent articles which can beformed from absorbent cores of the invention include diapers, femininesanitary napkins, and adult incontinence products.

Exemplary Embodiments of the Invention

Examples 1, 2, 4 and 5 were manufactured on a airlaid pilot machine madeby Danweb which has three forming heads, and to which has been added abetween-the-head SAP dosing system. In order to obtain more than threelayers, the structures were made by passing the web through the formingprocess more than once. On each pass the material was slightly pressedat the end of the line. The final thickness was adjusted on the lastpass. The SAP powder was placed in discrete lanes with the aid ofdivider boxes as depicted schematically in FIG. 9. which masks abouthalf of the area of the airlaid forming wire. The dividers in thefollowing Examples were 1.27 cm in width and the spaces between thedividers were 1.27 cm in width.

The raw materials used in the Examples are Foley Fluff (FF), a southernsoftwood bleached kraft fluff pulp, Buckeye Technologies Inc.; T-255polyolefin bicomponent fiber, 2.8 dpf, KoSa; 3024 cellulosic carriertissue, 18 gsm, Cellu Tissue Co; T-224 polyester fiber, 15 dpf×6 mm,KoSa; Sumitomo SA60S superabsorbent polymer granules, Sumitomo, Japan,Favor 880 superabsorbent polymer granules, Degussa, USA, Kolon GS3500superabsorbent polymer granules, Kolon, Korea and Airflex 124 latexemulsion, Air Products Chemicals.

The materials of Examples 1, 2, 4 and 5 have a plurality of layersproduced in two passes through the three head airlaying machine, withlayer 1 made first on the cellulosic carrier, followed by the first SAPfeed in lanes, followed by layer 2, followed by a second SAP feed inlanes, where the lanes of SAP from the second SAP feeder are offset inthe cross machine direction from the location of the lanes of SAP fromthe first SAP feeder, so that, looking at the material from the top downthe Z dimension perpendicular to the machine direction and the crossmachine direction, the lanes of SAP from successive feeds do notsuperimpose.

Below is given in reverse order the composition used to produce Examples1, 2, 4 and 5. SAP amounts in grams per square meter (gsm) for aparticular SAP feed are an overall basis weight for that feed. Since theSAP is laid down in lanes, the amount of SAP at successive locations inthe cross machine direction varies from zero or about zero between thelanes of SAP to about 100 percent in the lanes.

EXAMPLE 1 Basis Weight 323 μgsm, Caliper 1.2 mm

-   Layer 6: 10 gsm FF, 2.8 gsm bico, 1.0 gsm latex sprayed on top-   Between head SAP feeder 5: 52.6 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 5: 3.0 gsm FF, 1.0 gsm bico-   Between head SAP feeder 4: 52.6 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 4: 3.0 gsm FF, 1.0 gsm bico-   Between head SAP feeder 3: 52.6 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 3: 3.0 gsm FF, 1.0 gsm bico-   Between head SAP feeder 2: 52.6 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 2: 3.0 gsm FF, 1.0 gsm bico-   Between head SAP feeder 1: 52.6 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1: 9 gsm FF, 3.2 gsm bico-   Carrier: 18 gsm cellulosic tissue-   Sumitomo SA60S SAP was used in this example.

EXAMPLE 2 Basis weight 318 μm. Caliper 0.9 mm

-   Layer 6: 6.0 gsm FF, 1.5 gsm bico, 1.0 gsm latex sprayed on top-   Between head SAP feeder 5: 54.4 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 5: 2.0 gsm FF, 0.8 gsm bico-   Between head SAP feeder 4: 54.4 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 4: 2.0 gsm FF, 0.8 gsm bico-   Between head SAP feeder 3: 54.4 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 3: 2.0 gsm FF, 0.8 gsm bico-   Between head SAP feeder 2: 54.4 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 2: 2.0 gsm FF, 0.8 gsm bico-   Between head SAP feeder 1: 54.4 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1: 6.2 gsm FF, 2.1 gsm bico-   Carrier: 18 gsm cellulosic tissue-   Sumitomo SA60S SAP was used in this example.

EXAMPLE 4 Basis weight 323 μm, Caliper 1.3 mm

The first pass through the three head airlaid forming system laid thematerials in the amounts indicated below in reverse order, starting withHead 1 laying a FF and bico mixture on the cellulosic carrier tissue. Inthe second pass, layer 4 was laid by Head 3.

-   Layer4 (Head 3): 16.8 gsm PET Wellman 213×1 (6 dpf), 3.2 latex    Airflex 124-   Layer 3 (Head 3): 7.0 gsm FF, 3.0 gsm bico-   Between head SAP feeder 2: 127.5 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 2 (Head 2): 7.0 gsm FF, 3.0 gsm bico-   Between head SAP feeder 1: 127.5 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 7.0 gsm FF, 3.0 gsm bico-   Carrier: 18 gsm cellulosic tissue-   Sumitomo SA60S SAP was used in this example.

EXAMPLE 5 Basis weight 383 gsm Caliper 2.0 mm

The first pass through the three head airlaid forming system laid thematerials in the amounts indicated below in reverse order, starting withHead 1 laying a FF and bico mixture on the cellulosic carrier tissue.The second pass started with between head SAP feeder 1, followed byairlaying Layer 4 by Head 2.

-   Layer 5 (Head 3): 18.1 gsm FF, 7.7 gsm bico-   Between head SAP feeder 2: 71.3 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 4 (Head 2): 7.0 gsm FF, 3.0 gsm bico Between head SAP feeder    1: 71.3 gsm SAP, placed in 1.27 cm lanes, spaced 1.27 cm apart.-   Layer 3 (Head 3): 7.0 gsm FF, 3.0 gsm bico-   Between head SAP feeder 2: 71.3 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 2 (Head 2): 7.0 gsm FF, 3.0 gsm bico-   Between head SAP feeder 1: 71.3 gsm SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 14.0 gsm FF, 8.0 gsm bico-   Carrier: 18 gsm cellulosic-   Degussa FAVOR® 880 SAP was used in this example.

Comparative Example 3

A web was manufactured on the three-head Danweb airlaid machine with theSAP fed through the forming heads. The raw materials used were ND416compressible pulp, Weyerhaeuser, Tacoma Wash.; T-255 bicomponent fiber,2.8 dpf, KoSa; 3024 cellulosic carrier tissue, 18 gsm, Cellu Tissue Co;T-224 polyester fiber, 15 dpf×6 mm, KoSa; Kolon GS3500 superabsorbentpolymer granules, Kolon, Korea; and Airflex 124 latex emulsion, AirProducts Chemicals. The basis weight was 318 gsm, and the caliper was0.9 mm.

-   Layer 3: 36.0 gsm ND416, 5.0 gsm bico, 61.3 gsm SAP, 2.0 gsm latex    sprayed on top-   Layer 2: 35.0 gsm ND416, 5.0 gsm bico, 61.3 gsm SAP-   Layer 1: 35.0 gsm ND416, 5.0 gsm bico, 61.3 gsm SAP-   Carrier: 18 gsm cellulosic    Pliability

As used herein, “pliability” is the inverse of the amount of forcenecessary to bend a sheet of material of the invention. As the forcenecessary to bend the sheet increases, the pliability of the sheetdecreases.

Pliability can be measured by the following procedure, using a Gurleytester (Model 4171, Gurley Precision Instruments, Troy, NY).

-   1. Cut sample to 1 inch×3.25 inch as accurately as possible. If    there is a definite machine direction and cross direction, cut one    sample in each direction and test each.-   2. Fit custom clamp as shown in FIG. 3, over the original clamp    provided with the Gurley tester, and tighten smaller, upper    thumbscrews to secure (see FIG. 2 illustrating the custom clamp for    higher basis weight, lefty sheets). The custom clamp was designated    in such a way that it does not change the thickness of the tested    material, where the material is inserted into the clamp. If the    thickness is changed as a result of clamping then the properties of    the structure are changed and the results obtained by using the    Gurley tester are affected. In the present method, the clamp of FIG.    3 is used to eliminate such undesired effects.-   3. Open the custom clamp adjustable plate by loosening longer, lower    thumbscrews. Place sample in clamp by sliding sample up until it    just contacts original clamp. There should be 2.0 inches of sample    contained in the custom clamp.-   4. Adjust height of custom clamp by loosening height adjustment    screw on original clamp.

Adjust height so that a gap of 1.0 inch exists between the point wherethe sample exits the custom clamp and the point where the sample willcontact the lever arm.

-   5. Ensure that the remaining 0.25 inch of sample extends below the    top of the lever arm.

Ensure that lever arm is not moving. Press motor button to move sampletowards lever arm.

Continue pressing motor button until sample clears lever arm. Whiledoing this, observe and note the highest number reached on the scale.Repeat this in the opposite direction.

-   6. Average the two values obtained. In the conversion chart on the    apparatus, find the factor for a 1 inch wide×1.5 inch long sample    depending on the weight used and the distance the weight was placed    from the center on the lever arm. A 1.0 inch×3.25 inch sample tested    using the custom clamp corresponds to a 1.0 inch×1.5 inch sample    tested without using the custom clamp. Without the custom clamp,    0.25 inch of sample is in the original clamp, 0.25 inch extends    below the top of the lever arm, and 1-inch is the gap between. Using    the custom clamp, the same 0.25-inch number in the custom clamp is    used; the other 1.75-inch in the custom clamp secures the thicker    sample in place. The same 0.25-inch extends below the top of the    lever arm and the same one-inch gap is in between.

7. Multiply the average reading on the scale by the appropriateconversion factor found on the chart.

The result is Stiffness, which is expressed in milligrams force, mg.Pliability, P, is defined here according to the following formula:P=10⁶/9.81 *Stiffness.

The result, P, is expressed here in 1 per Newton, 1/N.

Table 1 below has data for Examples 1, 2, 4 and 5 of this invention,Comparative Example 3 and for several prior art materials which are usedin commercial products. TABLE 1 Basis SAP basis weight, weight, SAPPliability, Thickness, Material gsm gsm content, % 1/N mm Example 1 323263 81 918 1.2 Example 2 318 272 85 1250 0.9 Comparative 325 184 57 3342.0 Example 3 Example 4 233 255 79 486 1.3 Example 5 383 285 74 639 2.0Competitive 553 275 50 40 1.6 airlaid core Commercial 590 236 40 122 5.5diaper coreExamples 1, 2, 4 and 5: New bonded structuresExample 3: Prior-art bonded structureCompetitive airlaid core: Nova Thin, no binderCommercial diaper core Huggies, no binder

EXAMPLE 6 Basis weight 332 μm, Caliper 2.5 mm, Pliability 265 1/N

This structure was produced in three individual passes through the threehead airlaid line. During the first pass, the first forming headdeposited a mixture of 21.5 gsm Foley fluff and 2.3 gsm T-255 KoSa 2.8dpf bicomponent fibers onto an 18 gsm forming tissue from Cellutissue.Next 45.0 gsm of Kolon MG2600 from Kolon Chemical company was depositedin lanes onto the web. The second forming head added a mixture of 21.5gsm Foley fluff and 2.3 gsm T-255 KoSa 2.8 dpf bicomponent fibers. Afterthe structure was cured in an oven, 2.0 gsm AF-124 latex foam was addedto the tissue side of the absorbent. Basis weight at this point was 113gsm.

The second pass started by using the structure made in the first pass asthe carrier material. The first head added 3.0 gsm Foley fluff and 1.0gsm T-255 KoSa 2.8 dpf bicomponent fibers. Next 45.0 gsm of Kolon MG2600from Kolon Chemical company was deposited in lanes onto the web. Thisaddition of SAP to the web was aligned so the SAP lanes in the firststructure were not directly below. The second forming head added amixture of 21.5 gsm Foley fluff and 2.3 gsm T-255 KoSa 2.8 dpfbicomponent fibers. Again, 45.0 gsm of Kolon MG2600 from Kolon Chemicalcompany was deposited in lanes onto the web.

This addition of sap to the web was aligned so the first sap lanes werenot directly below the second. The third head deposited a mixture of21.5 gsm Foley fluff and 2.3 gsm T-255 KoSa 2.8 dpf bicomponent fibers.

The third pass started by using the structure made in the second pass asthe carrier material. Only the third head was used in this pass. Thethird head added a mixture of 27.0 gsm Wellman 213×1 6 dpf polyesterfibers and 53.0 gsm AL-Delta 6.7 dtx fibers from ES Fiber Visions. Thefinal thickness was reached by compaction of the web to 2.5 mm. Thebasis weight was 332 gsm.

EXAMPLE 7 Basis weight 140 μm Caliper 2.2 mm, Pliability 868 1/N

This structure was produced in two individual passes through the threehead airlaid line.

During the first pass, the first forming head deposited a mixture of20.0 gsm Foley fluff and 2.0 gsm T-255 KoSa 2.8 dpf bicomponent fibersonto an 18 gsm forming tissue from Cellutissue. Next 30.0 gsm of KolonMG2600 from Kolon Chemical company was deposited in lanes onto the web.The second forming head added a mixture of 21.0 gsm Foley fluff and 2.0gsm T-255 KoSa 2.8 dpf bicomponent fibers. Basis weight was 93 gsm atthis point.

The second pass started by using the structure made in the first pass asthe carrier material. Only the third head was used in this pass. Thethird head added a mixture of 17.0 gsm Wellman 213×1 6 dpf polyesterfibers and 33.0 gsm AL-Delta 6.7 dtx fibers from ES Fiber Visions. Thefinal thickness was reached by compaction of the web to 2.2 mm. Thebasis weight was 140 gsm.

EXAMPLE 8 Absorbent Core Thickness 4.12 mm, Pliability 116 1/N

An absorbent core was made by joining the material of Example 7 as anupper layer ASP (acquisition and storage ply) with the material ofExample 5 as a lower layer DSP (distribution and storage ply) in aDUOCORE absorbent core structure. The materials were joined by means ofa polymer spray adhesive, Super 77 available from 3 M, St. Paul, Minn.The area of the ASP was less than that of the DSP. An alternativeversion of this core with no adhesive was made as part of theacquisition time test procedure which follows.

Acquisition Time/Rewet/Wicking Distance Test Method

-   Equipment-   Saline solution, 0.9% (0.9% NaCl/deionized water by weight). Add    food-grade dye for better visibility if desired.-   Analytical balance, accurate/precise to +/−0.01 g.-   Timer graduated in seconds.-   Stopwatch graduated in hundredths of seconds.-   Plastic insult tube, 3.8 cm inside diameter (ID)×15.2 cm long (1.5    in ID×6 in).-   Foam, 40.6 cm long ×10.2 cm wide ×3.8 cm high (16 in ×4 in ×1.5 in).    The foam should have a hole cut into it. The center of the hole    should be located 10.2 cm from one of the ends (lengthwise) and    centered widthwise. The hole should have a diameter just large    enough to accommodate insertion of the plastic insult tube. The foam    should be covered with flexible plastic sheeting and sealed in any    appropriate way (heat seal, waterproof tape, etc.) such that a    waterproof barrier is created around the foam. Foam can be purchased    from Scott Fabrics, Memphis, Term.-   Gray weight plates, 40.6 cm long ×10.2 cm wide (16 in ×4 in). The    plates should weigh 2.9 kg (6.4 lb) to achieve a 0.69 kPa (0.1 psi)    load. Each plate should have a hole the same size and at the same    location as the hole in the foam piece.-   Black weight plate, 40.6 cm long ×10.2 cm wide (16 in ×4 in),    weighing enough to achieve a 0.69 kPa (0.1 psi) load when the foam    is used in conjunction with the plate. The plate should have a hole    the same size and at the same location as the hole in the foam    piece.-   Plastic board, 20.3 cm×43.2 cm (8 in ×17 in).-   Coverstock material, polypropylene spunbond treated with a durable    hydrophilic finish, 22 gsm. The coverstock material can be purchased    from Avgol Nonwoven Industries, Holon, Israel.-   Blotter paper, Grade S-22, cut to 40.6 cm long ×10.2 cm wide (16 in    ×4 in). The Grade S-22 paper can be purchased from Buckeye    Technologies, Memphis, Term.-   Ruler graduated in millimeters.-   Cylinder, graduated in tenths of milliliters.-   Procedure-   Assemble the sample (Duocore system) by placing ASP upper ply, cut    to 10 cm×20 cm, over one end of DSP lower ply, cut to 10 cm×40 cm.    Note that the polyester fiber layer of the ASP should face up and    the tissue side of the DSP should face down. Place the sample in the    test apparatus by placing sample on plastic board. Place the    coverstock material over the sample. Insert the plastic insult tube    into the foam. Position the foam piece on top of the sample; the    insult tube should be located over the ASP upper ply.-   Place one black weight and three gray weights over the foam piece to    achieve a 2.7 kPa (0.4 psi) load on the sample. FIG. 6 contains a    schematic diagram of the test apparatus.-   Set the timer for 20 minutes and place it beside the test apparatus.-   With the stopwatch in one hand and the graduated cylinder containing    75 ml of saline solution in the other hand, prepare to insult the    sample. Pour the fluid into the plastic insult cylinder. Start the    stopwatch at the moment the fluid strikes the sample. Empty the    fluid from the graduated cylinder as quickly as possible. Stop the    stopwatch when the fluid is absorbed by the sample.-   Record the time taken by sample to absorb fluid as the acquisition    time for the first insult.-   Start the 20-minute timer as soon as the fluid is absorbed by the    sample. Wait for 20 minutes.-   After the 20-minute waiting period, repeat steps 3-5 two more times    on the same sample in order to measure the acquisition times for the    second and third insults.-   After the third 20-minute waiting period, set the timer for 5    minutes and place it beside the test apparatus.-   Weigh a stack of 10 S-22 blotter papers. Record weight.-   Remove the weight over sample, the foam piece and the insult    cylinder.-   Place the stack of papers on the sample.-   Replace the foam and weights over the sample. Start the 5-minute    timer.-   At the end of 5 minutes, remove the weight and foam. Reweigh the    stack of papers. Record this second (wet) weight. The rewet,    expressed in grams, is the difference between the wet weight of the    papers and the dry weight of the papers.-   Find the furthest point fluid wicked to one end of the sample and    draw a line across the width of the sample at that point. Repeat the    same at the other end of the sample.-   Measure the distance in cm between the two lines. Record this number    as the wicking distance.

The result for this core was a 1^(st) insult acquisition time of 49.2seconds, 2^(nd) of 104 seconds and third of 129 seconds.

EXAMPLE 9 Absorbent Core Thickness 4.83 mm, Pliability 135 1/N

This core was made by the procedure used in Example 8, except that theASP was the material of Example 6 and the SAP was the material ofExample 5. The result for this core was a 1st insult acquisition time of42.9 seconds, 2nd of 80 seconds and third of 102 seconds.

Various materials, structures and manufacturing processes useful in thepractice of this invention are disclosed in U.S. Patent No.'s 6,241,713;6,353,148; 6,353,148;6,171,441; 6,159,335; 5,695,486; 6,344,109;5,068,079; 5,269,049; 5,693,162; 5,922,163; 6,007,643; and 6,355,079;and in U.S. Patent applications with serial numbers and filing dates,09/211,935 filed 12/15/98; 09/232,783 filed 1/19/99; 09/719,338 filed1/17/01; 09/475,850 filed 12/30/99; 09/469,930 filed 12/21/99;09/578,603 filed 5/25/00; 05/25/00; 05/593,409 filed 6/14/00; 09/325,764filed 6/8/99 allowed; 09/774,248 filed 1/30/01; and 09/854,179 filed5/11/01, all of which are hereby incorporated by reference in theirentirety. TABLE 2 Examples 11-15 Basis Weight, SAP Content, Pliability,Thickness, Example gsm % 1/N mm 11 250 75 3250 1.1 12 250 75 2760 1.1 13420 80  810 1.4 14 420 80  920 1.4 15 250 75 1900 1.1

Examples 11 through 15

-   All examples were manufactured on a 3-head airlaid pilot Danweb    machine with between-head SAP dosing systems. Examples 13 and 14    were formed in two stages. On the first pass through the forming    process, part of the web was formed, and then on the second pass the    remaining part of the structure was formed. On each pass the    material was slightly pressed at the end of the forming line. The    final thickness was adjusted on the last pass. The SAP powder was    placed in discrete lanes along the machine direction (MD). The lanes    were formed with the aid of divider boxes depicted in FIG. 9 of the    original application. The divider boxes were used that masked 50% of    the area of an airlaid forming wire. The dividers were 1.27 cm in    width and the voids between the dividers were 1.27 cm in width. With    this divider box, the same amount of SAP can be distributed over    half of the area, resulting in SAP stripes of twice the overall    basis weight.-   Any conventional means of dosing SAP onto an airlaid forming wire    may be used with the divider box shown in FIG. 9.    Raw materials:-   FOLEY FLUFF®, southern softwood bleached kraft fluff pulp, Buckeye    Technologies Inc.-   Treated FOLEY FLUFF®, as described in U.S. patent application Ser.    No. 09/469,930 filed Dec. 21, 1999, available from Buckeye    Technologies Inc. under the brand name CARESSA(TM),-   T-255 bicomponent fiber, 2.8 dpf, KoSa-   3024 cellulosic carrier tissue, 18 gsm, Cellu Tissue Co.-   10 gsm Avgol hydrophobic nonwoven carrier, Avgol, Israel-   Stockhausen SXM70 superabsorbent polymer granules, Degussa, USA-   Airflex 124 latex emulsion, 10% solids, Air Products Chemicals mixed    with 0.1% Aerosol OT

EXAMPLE 11

-   Latex spray applied on the top of the structure in an amount of 2    gsm (dry weight).-   Layer 3 (Head 3): 12.0 gsm FF, 5.0 gsm bico-   Between head SAP feeder 2: 94 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 2 (Head 2): 6.5 gsm FF, 2.5 gsm bico-   Between head SAP feeder 1: 94 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 11 gsm FF, 5.0 gsm bico-   Carrier: 18 gsm cellulosic-   * Overall basis weight

EXAMPLE 12

-   Latex spray applied on the top of the structure in an amount of 2    gsm (dry weight).-   Layer 3 (Head 3): 12.0 gsm FF, 5.0 gsm bico-   Between head SAP feeder 2: 98 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 2 (Head 2): 6.5 gsm FF, 2.5 gsm bico-   Between head SAP feeder 1: 98 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 11 gsm FF, 5.0 gsm bico-   Carrier: 10 gsm Avgol nonwoven-   *Overall basis weight

EXAMPLE 13

-   Pass I:-   Layer 6 (Head 3): 16.5 gsm FF, 5.0 gsm bico-   Between head SAP feeder 2: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 5 (Head 2): 5.7 gsm FF, 2.2 gsm bico-   Between head SAP feeder 1: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 4 (Head 1): 9.6 gsm FF, 4.4 gsm bico-   Carrier: 18 gsm cellulosic-   * Overall basis weight-   Pass II:-   Latex spray applied on the top of the structure in an amount of 2    gsm (dry weight).-   Layer 3 (Head 3): 16.5 gsm FF, 5.0 gsm bico-   Between head SAP feeder 2: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 2 (Head 2): 5.7 gsm FF, 2.2 gsm bico-   Between head SAP feeder 1: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 9.6 gsm FF, 4.4 gsm bico-   * Overall basis weight

EXAMPLE 14

-   Pass I:-   Layer 6 (Head 3): 16.5 gsm FF, 5.0 gsm bico-   Between head SAP feeder 2: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 5 (Head 2): 5.7 gsm FF, 2.2 gsm bico-   Between head SAP feeder 1: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 4 (Head 1): 13.6 gsm FF, 4.4 gsm bico-   Carrier: 10 gsm Avgol nonwoven-   * Overall basis weight-   Pass II:-   Latex spray applied on the top of the structure in an amount of 2    gsm (dry weight).-   Layer 3 (Head 3): 16.5 gsm FF, 5.0 gsm bico-   Between head SAP feeder 2: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart.-   Layer 2 (Head 2): 5.7 gsm FF, 2.2 gsm bico-   Between head SAP feeder 1: 78.3 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 13.6 gsm FF, 4.4 gsm bico-   * Overall basis weight

EXAMPLE 15

-   Latex spray applied on the top of the structure in an amount of 2    gsm (dry weight).-   Layer 3 (Head 3): 12.0 gsm SW-16, 5.0 gsm bico-   Between head SAP feeder 2: 94 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 2 (Head 2): 6.5 gsm SW-16, 2.5 gsm bico-   Between head SAP feeder 1: 94 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 11 gsm SW-16, 5.0 gsm bico-   Carrier: 18 gsm cellulosic-   * Overall basis weight    Effect of Folding of Absorbent Core on Its Acquisition Properties

It was discovered that folding of structures described in the inventionresults in significant improvement in their acquisition properties. Thisimprovement is illustrated with but not limited to the examplessummarized in Table 3. Based on these results we can see improvements ofthe performance of the folded structures over the unfolded sampleshaving the same overall basis weight as the folded ones in the foldedconfiguration (see FIG. 11). These improvements are significantlyshorter acquisition times and also lower rewet values. TABLE 3 BW, gsmOverall BW Fluid Intake Un- after SAP Time, s Example folded C-folding*)Type % 1st 2nd Rewet g 11 250 420 SXM70 75 176 422 12.3 C-folded (seeFIG. 11) 13 420 — SXM70 75 1594 3600 13.9 12 250 420 SXM70 75 225 3279.2 C-folded (see FIG. 11) 14 420 — SXM70 75 1354 3147 20.2*)C-folding: A 21.7 cm wide by 66 cm long material, each edge was foldedover approximately 4.3 cm dividing the layer into thirds (4.3 cm folded,4.3 cm unfolded open, 4.3 cm folded) for a total width of about 13 cm(see cross-sections folded and unfolded sheets, FIG. 11)

-   3. Effect of Treated FOLEY FLUFF® (TFF) on Capacity and Acquisition-   MoliCare Plus AI diapers from Hartmann were used as control    products. The absorbent is in three layers, curly fiber acquisition    layer, sap-fluff layer and a fluff back layer against the poly    backsheet. The diapers were taken apart by carefully peeling the    fluff back layer from the sap-fluff layer. Then the SAP-fluff layer    was peeled from the coverstock and curly fibers. The airlaid core    was then placed on the fluff back layer and covered by the curly    fibers and topsheet. The curly fibers were not removed from the    topsheet. One of the inserted cores, that is Example 11, contained    FOLEY FLUFF® as cellulosic fiber component and the other contained    Treated FOLEY FLUFF®. The width of the airlaid inserts in the    obtained Absorbent Systems I was 13 cm and their length was 66 cm.

The results in Table 4 illustrate the effect of the Treated FOLEYFLUFF®on the performance of the Absorbent System I composed of thetopsheet, curly-fiber layer, airlaid insert, fluff and poly backsheet.As seen from the data, the acquisition of Example 15 with Treated FOLEYFLUFF® was significantly faster than the acquisition of Example 11 withFOLEY FLUFF®. The sample with SW-16 fibers had also improved capacityover the sample with FF. TABLE 4 Capacity @ 0.4 psi Absorbent System 1Core Material SAP of airlaid inserts only Fluid Intake Time, s fromExample BW, gsm Type % Fiber 13 cm × 40.6 cm g/g 1st 2nd 3rd 11 253SXM70 75 FF 218 16.3 94 287 412 (SD 3.8) (SD 0.45) 15 252 SXM70 75 TFF248 18.7 75 239 360 (SD 2.5) (SD 0.15)

-   4. Effect of Treated FOLEY FLUFF®on Fluid Intake of Folded High-SAP    Airlaid

MoliCare Super AI diapers from Hartmann (as above) were used as controlproducts. In this case the airlaid cores were first C-folded as shown inFIG. 11 and then placed on the fluff back layer and covered by the curlyfibers and topsheet. The curly fibers were not removed from thetopsheet. One of the inserted cores, that is C-folded Example 11contained FOLEY FLUFF® as cellulosic fiber component and the other,Example 15, contained Treated FOLEY FLUFF®. The width of the airlaidinserts was 13 cm and their length was 66 cm. The results in Table 5illustrate the effect of the Treated FOLEY FLUFF® and C-folding on theperformance of the Absorbent System 2 composed of the topsheet,curly-fiber layer, airlaid insert, fluff and poly backsheet. As seenfrom the data, the acquisition of the C-folded EXAMPLE 15 WITH TREATEDFOLEY FLUFF® was significantly faster than the acquisition of theC-folded Example 11 with FOLEY FLUFF®. The sample with Treated FOLEYFLUFF® fibers had also improved capacity over the sample with FOLEYFLUFF®. TABLE 5 Core Material from Example, Absorbent System 2 C-FoldedSAP Fluid Intake Time, s (see FIG. 11) Type % Fiber 1st 2nd 3rd 11 SXM7075 FF 64 161 265 15 SXM70 75 TFF 50 119 190Effect of Bonded Acquisition Ply and Treated FOLEY FLUFF® on FluidIntake of Folded High-SAP Airlaid in Whole Absorbent System

To make a bonded acquisition pad, several MoliCare Super diapers weretaken apart and the acquisition pads removed. The removed curly fiberswere then used to make an airlaid handsheet using a lab pad blowingapparatus, with an addition of 8% KoSa T-255, 2.8 dpf fibers. The padwas cured at 160 C for 10 minutes. These acquisition pads had basisweight of about 159 gsm and their thickness was about 3.8 mm. The basisweight of the unbonded acquisition layers of curly fibers in theoriginal diapers was about 154 gsm and their thickness was about 2.0 mm.They were added to the Molicare Super diaper shell along with Example15. Example 15 was in a C-fold configuration as shown in FIG. 11. Theresults shown in Table 6 indicate that the Absorbent Systems 2 withC-folded airlaid inserts containing Treated FOLEY FLUFF® fibers and withbonded acquisition layers had better acquisition performance than theoriginal diapers. TABLE 6 Example for Absorbent High-SAP System 2Airlaid (see FIG. 3) Component Curly Fiber Overall Mass Fiber in FluidIntake Unfolded/ Acquisition of Absorbent High-SAP Time, s C-Folded PlySystem, g Airlaid 1st 2nd 3rd 14 Unbonded 72 FF 67 197 310 Unfolded 11Unbonded 73 FF 64 161 265 C-Folded (see FIG. 1) 15 Unbonded 73 TFF 50119 190 C-Folded (see FIG. 1) 15 Bonded 73 TFF 25 61 100 C-Folded (seeFIG. 1) Unbonded Unbonded 114 — 53 108 144 Control

EXAMPLES 16 THROUGH 18

All examples were manufactured on a 3-head airlaid pilot Danweb machinewith 2 between-head SAP dosing systems. The SAP powder was placed indiscrete lanes along the machine direction (MD). The lanes were formedwith the aid of divider boxes depicted in FIG. 9 of the originalapplication. The divider boxes were used that masked 50% of the area ofan airlaid forming wire. The dividers were 1.27 cm in width and thevoids between the dividers were 1.27 cm in width. With this divider box,the same amount of SAP can be distributed over half of the area,resulting in SAP stripes of twice the overall basis weight.

The structures of Examples 17 and 18 comprise a thicker layer of bondedcellulose fibers for enhanced wicking performance.

Any conventional means of dosing SAP onto an airlaid forming wire may beused with the divider box shown in FIG. 9.

Raw materials:

-   FOLEY FLUFF®, southern softwood bleached kraft fluff pulp, Buckeye    Technologies Inc.-   Treated FOLEY FLUFF®, as described in U.S. patent application Ser.    No. 09/469,930 filed Dec. 21, 1999, available from Buckeye    Technologies Inc. under the brand name CARESSA(TM),-   T-255 bicomponent fiber, 2.8 dpf, KoSa-   Carrier: 10 gsm Avgol hydrophilic nonwoven carrier, Avgol, Israel-   SAP: Stockhausen Z 1102 superabsorbent polymer granules, Degussa,    USA-   Airflex 124 latex emulsion, 10% solids, Air Products Chemicals mixed    with 0.1% Aerosol OT

EXAMPLE 16

-   Latex spray applied on the top of the structure in an amount of 5.0    gsm (dry weight).-   Layer 3 (Head 3): 20.0 gsm Caressa, 1.5 gsm bico-   Between head SAP feeder 2: 94 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder I do not superimpose)-   Layer 2 (Head 2): 6.5 gsm Caressa, 1.5 gsm bico-   Between head SAP feeder 1: 94 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 11 gsm Caressa, 1.5 gsm bico-   Carrier: 10 gsm Avgol nonwoven-   Latex applied on the bottom of the structure in an amount of 5.0 gsm    (dry weight).-   Overall basis weight

EXAMPLE 17

-   Latex spray applied on the top of the structure in an amount of 5.0    gsm (dry weight).-   Layer 3 (Head 3): 20 gsm Caressa, 1.5 gsm bico-   Between head SAP feeder 2: 100 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 2 (Head 2): 6.5 gsm FF, 1.5 gsm bico-   Between head SAP feeder 1: 100 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 84 gsm FF, 1.5 gsm bico-   Carrier: 10 gsm Avgol nonwoven-   Latex applied on the bottom of the structure in an amount of 5.0 gsm    (dry weight).-   *Overall basis weight

EXAMPLE 18

-   Latex spray applied on the top of the structure in an amount of 5.0    gsm (dry weight).-   Layer 3 (Head 3): 84 gsm FF, 1.5 gsm bico-   Between head SAP feeder 2: 100 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart. (the SAP lanes formed under SAP feeder 2 and    the SAP lanes formed under SAP feeder 1 do not superimpose)-   Layer 2 (Head 2): 6.5 gsm FF, 1.5 gsm bico-   Between head SAP feeder 1: 100 gsm* SAP, placed in 1.27 cm lanes,    spaced 1.27 cm apart-   Layer 1 (Head 1): 20 gsm Caressa, 1.5 gsm bico-   Carrier: 10 gsm Avgol nonwoven-   Latex applied on the bottom of the structure in an amount of 5.0 gsm    (dry weight).

*Overall basis weight TABLE 7 Basis Capacity @ weight, Content ofThickness, Pliability, 0.4 psi, Example gsm SAP, % mm 1/N g/g Example 16250 75 1.1 3265 21.8 Example 17 335 60 1.3 1340 22.5 Example 18 335 601.4 1505 22.8

1. A material comprising (A) from about 60 weight percent to about 95 weight percent SAP, (B) from about 5 weight percent to about 40 weight percent fibers, (C) from about 0.1 weight percent to about 30 weight percent total binder, and having (D) a basis weight of from about 100 gsm to about 1000 gsm, (E) a density of from about 0.15 g/cc to about 3 g/cc, the material having (F) a thickness Z dimension of from about 0.3 mm to about 3 mm, and (G) a pliability of about 400 1/N or greater.
 2. The material of claim 1, wherein the material is a nonwoven material.
 3. The material of one of the previous claims, wherein the material comprises from about 70 weight percent to about 95 weight percent SAP.
 4. The material of one of the previous claims, wherein the material comprises from about 80 weight percent to about 95 weight percent SAP.
 5. The material of one of the previous claims, wherein the material comprises from about 85 weight percent to about 95 weight percent SAP.
 6. The material of one of the previous claims, wherein the material comprises from about 5 weight percent to about 30 weight percent fibers.
 7. The material of one of the previous claims, wherein the material comprises from about S weight percent to about 20 weight percent fibers.
 8. The material of one of the previous claims, wherein the material comprises from about 5 weight percent to about 15 weight percent fibers.
 9. The material of one of the previous claims, wherein the material comprises from about 0.1 weight percent to about 10 weight percent total binder which comprises a first binder, a second binder, and, optionally, a third binder, where each binder can be the same as or different from any other binder.
 10. The material of one of the previous claims, wherein the material comprises from about 0.3 weight percent to about 6 weight percent total binder.
 11. The material of one of the previous claims, wherein the material comprises from about 0.5 weight percent to about 4 weight percent total binder.
 12. The material of one of the previous claims, wherein the material has a basis weight of from about 200 gsm to about 700 gsm.
 13. The material of one of the previous claims, wherein the material has a basis weight of from about 250 gsm to about 500 gsm.
 14. The material of one of the previous claims, wherein the material comprises has a basis weight of from about 300 gsm to about 450 gsm.
 15. The material of one of the previous claims, wherein the material has a density of from about 0.2 g/cc to about 1 g/cc.
 16. The material of one of the previous claims, wherein the material has a density of from about 0.22 g/cc to about 0.8 g/cc.
 17. The material of one of the previous claims, wherein the material has a density of from about 0.24 g/cc to about 0.6 g/cc.
 18. The material of one of the previous claims, wherein the material has a thickness Z dimension of from about 0.3 mm to about 2 mm.
 19. The material of one of the previous claims, wherein the material has a thickness Z dimension of from about 0.3 mm to about 1.5 mm.
 20. The material of one of the previous claims, wherein the material has a pliability of about 500 1/N or greater.
 21. The material of one of the previous claims, wherein the material has a pliability of about 600 1/N or greater.
 22. The material of one of the previous claims, wherein the material has a pliability of about 700 1/N or greater.
 23. The material of one of the previous claims, wherein the material has a pliability of about 800 1/N or greater.
 24. The material of one of the previous claims, wherein the material has a pliability of about 900 1/N or greater.
 25. The material of one of the previous claims, wherein the material has a pliability of about 1200 1/N or greater.
 26. The material of one of the previous claims further comprising (H) a carrier.
 27. The material of one of the previous claims, wherein the carrier comprises natural, synthetic, or a mixture of natural and synthetic materials.
 28. The material of one of the previous claims, wherein the carrier comprises natural fibers, synthetic fibers, or natural and synthetic fibers.
 29. The material of one of the previous claims, wherein the carrier comprises cellulosic fibers.
 30. The material of one of the previous claims, wherein the carrier has a basis weight of from about 2 gsm to about 40 gsm.
 31. The material of one of the previous claims, wherein the carrier has a basis weight of from about 5 gsm to-about 30 gsm.
 32. The material of one of the previous claims, wherein the carrier has a basis weight of from about 10 gsm to about 25 gsm.
 33. The material of one of the previous claims further comprising (I) a layer consisting essentially of (a) synthetic fibers, and (b) a third binder.
 34. The material of one of the previous claims, wherein the synthetic fibers in the layer are polyester fibers.
 35. The material of one of the previous claims, wherein the layer has a basis weight of from about 20 gsm to about 50 gsm.
 36. The material of one of the previous claims, wherein the first binder is a bicomponent fiber.
 37. The material of one of the previous claims, wherein the first binder is an emulsion polymer.
 38. The material of one of the previous claims, wherein the second binder is a bicomponent fiber.
 39. The material of one of the previous claims, wherein the second binder is an emulsion polymer binder.
 40. The material of one of the previous claims, wherein the third binder is a bicomponent fiber.
 41. The material of one of the previous claims, wherein the third binder is an emulsion polymer binder.
 42. The material of one of the previous claims, wherein different binders are in different parts of the material.
 43. The material of one of the previous claims, wherein the same binder is in different parts of the material.
 44. The material of one of the previous claims, wherein different binders are in the same part of the material.
 45. The material of one of the previous claims, wherein at least two binders are different from each other.
 46. The material of one of the previous claims, wherein the material has been produced in a series of unit operations in a continuous process.
 47. The material of one of the previous claims, wherein the continuous process comprises airlaying by means of one or more forming heads.
 48. The material of one of the previous claims, wherein the material has (J) a machine direction ×dimension of from about 1 cm to about 1000 m (K) a cross machine direction Y dimension of from about 2 cm to about 5 m, and the material is in a substantially rectangular format and from about 90 weight percent to about 100 weight percent of the SAP in the material is located in SAP domains with a longest dimension aligned substantially in the machine direction X of the material.
 49. A nonwoven material with a pliability of about 400 1/N or greater comprising from about 75 to about 95 weight percent SAP.
 50. The nonwoven material of claim 49 comprising from about 80 to about 95 weight percent SAP.
 51. The nonwoven material of one of claims 49-50 comprising from about 85 to about 95 weight percent SAP.
 52. The nonwoven material of one of claims 49-51 having a pliability of about 500 1/N or greater.
 53. The nonwoven material of one of claims 49-52 having a pliability of about 600 1/N or greater.
 54. The nonwoven material of one of claims 49-53 having a pliability of about 700 1/N or greater.
 55. The nonwoven material of one of claims 49-54 having a pliability of about 800 1/N or greater.
 56. A process for the production of a material comprising depositing on a removable support or a carrier a mixture of SAP, fibers and binder, where the material comprises from about 60 weight percent to about 95 weight percent SAP and has a pliability of about 400 1/N or greater.
 57. A multistrata fibrous web comprising: (a) a plurality of first strata comprising matrix fibers and thermoplastic fibers; (b) a plurality of second strata comprising functional particles arranged in separated lanes; (c) wherein the first and second strata alternate through the web and the lanes of the second strata are arranged such that the lanes of adjacent second strata do not superimpose, or (d) wherein the arrangement of the first and second strata is random.
 58. The web of claim 57, wherein the lateral edges of the web are particle free.
 59. The web of either of claims 57 or 58 wherein the lanes are parallel.
 60. The web of any of claims 57-59 wherein the particles of the second strata cover at least 50% of the surface area of the stratum.
 61. The web of any of claims 57-60 wherein the web includes 2, 3, 4, 4 or 6 second strata.
 62. The web of any of claims 57-61 wherein the particles are SAP particles.
 63. The web of any of claims 57-62 wherein the lanes are not continuous.
 64. The web of any of claims 57-62 wherein the lanes are S-shaped.
 65. The web of any of claims 57-62 wherein the lanes are hourglass-shaped.
 66. A process for the production of a material comprising depositing on a removable support, a carrier or on a carrier on a support a mixture of SAP, fibers and binder, where the material comprises from about 60 weight percent to about 95 weight percent SAP and has a pliability of about 400 1/N or greater.
 67. The process of claim 66, wherein (a) a layer of fibers and binder is deposited on a moving removable support, a carrier or on a carrier on a support to form a web, the movement being in a machine direction X, (b) SAP is deposited in discreet lanes on the web of (a) in the machine direction, the lanes being spaced apart in the cross machine direction Y at a right angle to the machine direction, (c) a second layer of fibers and binder is deposited on the moving web, (d) a second layer of SAP is deposited in discreet lanes on the web of (c) in the machine direction, the lanes being spaced apart in the cross machine direction, where the SAP lanes of the second layer are not superimposed on the SAP lanes of the first layer when viewed from a thickness direction Z at right angles to the X and Y directions, or where the arrangement of the first and second layers of SAP lanes is random, (e) optionally repeating steps (c) and (d) one or more times, (f) heating the web one or more times to activate the binder, (g) optionally densifying the web.
 68. An absorbent core comprising: (1) a material of one of the previous claims in combination with (2) a second material, where the second material is a second layer of the material of (1), a material of one of the previous claims which is not the material of (1), or a second material which is not a material of one of the previous claims.
 69. A process for the production of an absorbent core comprising combining (1) a material of one of the previous claims with (2) a second material, where the second material is a second layer of the material of (1), a material of one of the previous claims which is not the material of (1), or a second material which is not a material of one of the previous claims.
 70. The absorbent core of claim 68 or 69, wherein the second material is a SAP containing material in which the SAP is in one layer of a single layer or multilayer second material and where the sap is substantially evenly distributed in the layer.
 71. The absorbent core of one of claims 68-70, wherein the material and the second material combined by means of an adhesive.
 72. An absorbent product comprising the material of one of claims 1-48, the nonwoven material of one of claims 49-55, the material produced by the process of one of claims 66-67, or the web of one of claims 57-65 and one or more of (a) a fluid pervious topsheet, (b) a fluid impervious backsheet.
 73. The absorbent product of claim 72 in the form of a diaper, training pant, incontinent device, feminine hygiene device, surgical drape, wound dressing, or cable wrap. 